NSInvalidArgument錯誤 - 來自CIImage的CGImageRef

Question

我在兩天前運行正常的一些代碼上出現錯誤。錯誤是：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFType extent]: unrecognized selector sent to instance 0x1bc8f0' 

它指向此行的main.m：

return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class])); 

使用日誌，看看我的代碼到達看來這行引發錯誤：

greySave = [context createCGImage:greyscaleImage fromRect:[greyscaleImage extent]]; 

greySave是一個CGImageRef，在我的視圖控制器的開始聲明。這是簡單的抓住一個CIImage輸出並將其轉變成一個CGImageRef保存：

desaturate = [CIFilter filterWithName:@"CIColorMonochrome" keysAndValues:kCIInputImageKey, colourSave, @"inputIntensity", [NSNumber numberWithFloat:0.00], nil]; 


greyscaleImage = [desaturate valueForKey:@"outputImage"]; 


greySave = [context createCGImage:greyscaleImage fromRect:[greyscaleImage extent]]; 

的唯一的事情我已經改變了，我認爲（雖然不明白爲什麼）可能會導致問題增加一個額外的條件語句，這將應用第二個過濾器是用戶希望這樣做：

if ([_alphaButtonSavedState isEqualToString:@"ON"]) { 
      NSLog(@"user does want alpha on greyscale"); 
      //user wants alpha mask also 
     } else { 
      NSLog(@"user does not want alpha on greyscale"); 
      //convert to CGImage for saving 
      greySave = [context createCGImage:greyscaleImage fromRect:[greyscaleImage extent]]; 
      NSLog(@"greySave cgimage created"); 

      //save the grey image 
      [library writeImageToSavedPhotosAlbum:greySave metadata:[greyscaleImage properties] completionBlock:^(NSURL *assetURL, NSError *error){ 
       if (error) { 
        NSLog(@"ERROR in greyscale save: %@", error); 
       } else 
       { 
        NSLog(@"SUCCESS in greyscale save"); 
        //in here we'll put a nice animation or something 
        //CGImageRelease(greyscaleImage); 
       } 
      }]; 

任何想法爲什麼會發生這種情況？

謝謝。

編輯：

這裏是整個代碼塊，以防萬一有幫助。

[stillImage captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler:^(CMSampleBufferRef imageSampleBuffer, NSError *error) { 

    NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageSampleBuffer]; //get the raw image data from the session 
    UIImage *startImage = [[UIImage alloc] initWithData:imageData]; //create a UIImage from that image data, let's us work with it 

    //resizing of image to take place before anything else 
    UIImage *image = [UIImage imageWithImage:startImage scaledToSize:_exportSSize]; //scale the image so it's shortest side is the size given in prefs 

    NSLog(@"image width post scale: %g", image.size.width); 
    NSLog(@"image height post scale is: %g", image.size.height); 

    //change the context to render using cpu, so on app exit renders get completed 
    context = [CIContext contextWithOptions: [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:kCIContextUseSoftwareRenderer]]; 

    //new crop testing - not using CIImage - seems to work, just need to sort out crop region 
    CGRect cropRect = CGRectMake(0, 0, _exportSize, _exportSize); 
    UIImage *cropper = [self imageByCropping:image toRect:cropRect]; 

    //the colour image is always saved so create a CGImage to save later 
    colourSave = [cropper CGImage]; 
    NSLog(@"coloursave image created"); 

    //now we convert and create CGImages based upon chosen export options 
    if ([_greyButtonSavedState isEqualToString:@"ON"]) { 
     NSLog(@"inside the greyscale conditional"); 
     //user wants greyscale image 
     //create a CIMonochrome filter 
     desaturate = [CIFilter filterWithName:@"CIColorMonochrome" keysAndValues:kCIInputImageKey, colourSave, @"inputIntensity", [NSNumber numberWithFloat:0.00], nil]; 
     NSLog(@"desat ci filter created"); 
     //get the output 
     greyscaleImage = [desaturate valueForKey:@"outputImage"]; 
     NSLog(@"dest output image created"); 

     //if the user wants to add the alpha 
     if ([_alphaButtonSavedState isEqualToString:@"ON"]) { 
      NSLog(@"user does want alpha on greyscale"); 
      //user wants alpha mask also 
     } else { 
      NSLog(@"user does not want alpha on greyscale"); 
      //convert to CGImage for saving 
      greySave = [context createCGImage:greyscaleImage fromRect:[greyscaleImage extent]]; 
      NSLog(@"greySave cgimage created"); 

      //save the grey image 
      [library writeImageToSavedPhotosAlbum:greySave metadata:[greyscaleImage properties] completionBlock:^(NSURL *assetURL, NSError *error){ 
       if (error) { 
        NSLog(@"ERROR in greyscale save: %@", error); 
       } else 
       { 
        NSLog(@"SUCCESS in greyscale save"); 
        //in here we'll put a nice animation or something 
       } 
      }]; 
     } 
    } 

- 在這裏兩個條件語句，無論現在還是空

- 後跟一個保存的colourSave圖像，這工作正常。

- 然後該方法結束。

還有一件事，這是我如何裁剪圖像。從下面的方法返回的圖像是我創建從CIImage：

-(UIImage *)imageByCropping:(UIImage *)imageToCrop toRect:(CGRect)rect 

{ CGImageRef imageRef = CGImageCreateWithImageInRect（[imageToCrop CGImage]，RECT）;

UIImage *cropped = [UIImage imageWithCGImage:imageRef]; 
CGImageRelease(imageRef); 

return cropped; 

}

Answer 1

增加的情況下，它可以幫助別人的答案。

我正在傳遞一個UIImage到CIFilter，這是造成這個問題。將UIImage轉換爲CIImage並通過解決問題。